Spacewalk success, but spacesuit issues delay NASA’s next procedure

NASA needs an extra day to resize a backup spacesuit for one of its astronauts.

NASA's spacewalk yesterday was a tactical success, as astronauts Rick Mastracchio and Michael Hopkins removed a bad valve from the ammonia pump in five hours and 28 minutes—an hour faster than the 6.5-hour exercise originally planned. However, midway through the procedure, Mastracchio encountered an issue with his spacesuit that has caused NASA to delay the second of three possible missions until Tuesday.

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Mastracchio started experiencing unusually cold toes during the operation, pumping up the heat inside his boots in order to continue in relative comfort. Based on the two astronaut's efficiency, NASA initially intended to get ahead of schedule with extra work yesterday. However, about two hours after Mastracchio started experiencing difficulty, he respectfully declined when Mission Control spoke of additional work. "I'd like to stow this old module and kind of clean up and call it a day," he said.

According to NPR, the suits worn on Saturday had already been altered in response to helmet flooding that nearly drowned an Italian astronaut during the summer. So Mastracchio and Hopkins went into yesterday's mission with extra safety gear—snorkels in their suits and water-absorbent pads within their helmets.

The new issue is not related to any of those changes. According to Deutsche Welle, the problem is with how the sublimator (a cooling unit) in Mastracchio's suit operated when entering ISS airlock. NASA said the question is whether water entered the sublimator at that time. "During repressurization of the station's airlock following the spacewalk, a spacesuit configuration issue put the suit Mastracchio was wearing in question for the next excursion," NASA said in a statement. Delaying the next steps of the valve replacement from Monday until Tuesday will give NASA time to address the issue. Mastracchio is scheduled to wear a backup suit and needs this time to have it resized.

According to Weather.com, the initial NASA plan was to disconnect the pump Saturday, remove it on Monday, and to hookup the new pump on Wednesday. However, Saturday's work included disconnecting the large pump assembly and securing it in a new location on the outside of the ISS. It was enough progress that despite the spacesuit issue, NASA may only need two exercises rather than three to finish the procedure.

Only thing...Why can't they make them like the use to? Remember the Moon walks in the 70's... Worked fine.

There is gravity on the moon. Any excess water in the suit would drain to their feet, so they'd be able to breathe just fine.

The Apollo suits were also used for less than a week, and went through maybe 5 compression/decompression cycles. The suits on the ISS sit up there generally for around 2 years each before being cycled down for refit, and have to go through many more compression/decompression cycles, as well as having components swapped out to accommodate different sized astronauts. Admittedly, the Apollo suits had to operate in a hostile dust environment.

I'm a little surprised we still do everything with spacesuits like this. If you had asked me 15 years ago how I thought we would be doing maintenance on the ISS in 2013, I would have said Waldo units. Space suits are so bulky and exhausting that it seemed like robotics would take over the job pretty quickly. It's not like there is a major advantage in having the person right there. They get little to no tactile feedback and can't move quick enough to deal with emergencies and there are lots of extra risks from having a person out there in what is effectively a cloth spacecraft.

That's pretty much what DEXTRE (and possible Robonaut R2, though that's designed to be autonomous and currently isn't vacuum rated) is for: remote manipulation from a comfortable environment (either inside the ISS, or from the ground). The problem is that while you have eliminated physical fatigue, you have the high mental fatigue of using a remote manipulator. Haptic feedback is minimal (especially as you don;t want to be touching things unnecessarily) and proprioceptive feedback is almost nonexistent.

There are kind of three schools of spacesuit design: the current pressure-suite-and-support-backpack (with a few rigid torso bits) design; the hardsuit with Waldo manipulators for the hands (very much like the WASP Atmospheric Diving Suit) which is pretty much a small rigid spaceship with arms; and the Space Activity Suit (or 'skinsuit'), where counterpressure is provided mechanically by elasticated fabric allowing for much greater flexibility, but needs to be fitted very closely and getting in and out is an unsolved problem (as is plumbing).

It seems to me that getting natural feeling force feedback to work on a remote system shouldn't be an impossible problem. It's not like you get fine grained light touch feedback with pressurized gloves today.